Biking tips

How to… fix your motorcycle DIY mistakes

engine maintenance

While the UK, along with the rest of the world, is on lockdown due to the COVID-19 outbreak, many of us are spending extended amounts of time in our garages, carrying out maintenance and making modifications to our motorcycles. When everything is going well, spending time with your bike and with your tools can be one of the most satisfying experiences. But when it goes wrong, it can be one of the most frustrating, and for the rookie DIY mechanics, we have to accept the odd mistake will happen.

Thankfully they can (usually) be fixed. Whether you’ve dropped a bolt in the bodywork (or worse), spilt some fluid on your fairing, snapped a bolt head or can’t remember which order you disassembled something, it’s all easily done, and we’ve all been there! Preventing something like this from happening is always better than trying to rectify it once it has, but if the worst does happen, there are ways around them. For example…

Snapped heads

Substandard lubrication, corrosion, and being exposed to the elements can cause bolts to seize, and too much force to a seized fastener can round off the head or even snap it off completely. Prepare any fastener prone to seizing with dedicated penetrating fluid (not an all-in-one oil) beforehand and apply a swift and direct hit with a mallet to help break its grip. Heat can also ease the very worst seized bolts.

How to fix: If a sheared bolt still has a protruding end, grip it with pliers or mole grips and try to pull it free. Fasteners that have snapped flush will likely need to be drilled out, or a new grip point will need to be fashioned. You can do this by welding on a nut to the sheared bolt, which does require specialist equipment.

Stripped threads

It’s not too difficult to strip the threads on your motorcycle. Most bikes have lots of soft cast alloy held together with hard steel bolts. Fit bolts by hand for the first few turns so any cross-threading can be easily felt and rectified, and once you’re satisfied with the fit, use a torque wrench to accurately tighten. You should only apply grease or threadlock to bolts where your bike’s manual specifies.

How to fix: If you have stripped a thread, use thread inserts for minor bolts. For more serious issues, drilling and re-tapping will be required, or welding, re-drilling and re-tapping for the very worst cases. It’s a fairly common issue, so tools are available from the usual retailers.

The dreaded drop

Dropping a washer, nut or bolt into the fairing is extremely annoying and always seems to take longer than you think to find. But extra care needs to be taken when working around open air boxes, fuel systems, intake ports and uncovered engines. One 10mm nut dropped into the head or cam chain tunnel could mean you need to strip down the engine.

Make sure that anything removed is securely held and put to one side, well out of the way. Cover up any openings when you’re not accessing them with clean rag or tissue to stop anything accidentally falling in.

How to fix: A telescopic magnet should do the job to retrieve any fallen debris. If not, don’t ignore it and hope for the best, otherwise your engine will be ruined. Dismantle the part where the item has fallen and retrieve it.

Brake fluid spillage

Servicing your brakes is essential, simple and rewarding, but brake fluid is unpleasant and extremely corrosive. Any spillages of brake fluid left unchecked will eat through your bike’s paint, which putting right could potentially lead to a costly bill.

Have fresh water and cloth to hand to wipe up any spillages immediately, and make sure that any container or bleeding equipment with new or used fluid in has a lid and is placed completely out of the way. Surround reservoirs with rag to catch any drips and place some cardboard behind the calliper to stop splashes getting on the wheel or mudguard.

How to fix: After quickly wiping up any spills, you may need to touch up the paintwork. Any spillages that have been left for a period of time will almost certainly corrode paint and refinishing will be needed.

Shorting electrics

Working with your motorcycle’s electrics should be taken very seriously, and shorting terminals with tools or touching live feeds isn’t recommended. 12 volts is more than enough electricity to cause damage to your bike, give you a nasty shock and even cause a fire. The good news is that the solution to safely working on your bike’s electrics is simple – disconnect and remove the battery to avoid any nasty accidents.

How to fix: It may be as easy as a new fuse, but in some cases you may need to replace fried components or even the whole wiring loom.


Putting your bike back together after doing some maintenance or modifications can feel like you’re on the home stretch. Concentration can lapse and mistakes creep in, and before you know it, things aren’t being put back together in the correct order. Treat reassembly with the same care and attention as the main part of the job to give you peace of mind that everything’s back as it should be.

How to fix: Take notes on what order things have been removed so you can reverse it when it needs putting back together. Think the job through and read the manual to make sure you only have to do it once, and that it’s done right.

Biking Tips, Inside Bikes

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